Method of producing quinones



Patented Apr. 3, 1945 UNITED STATES PATENT omen METHOD OF PRODUCING QUINONES Richard T. Arnold, Minneapolis, Minn., assignor to Regents of the University of Minnesota, Minneapolis, Minn., a corporation of Minne-' sota No Drawing. Application April 30, 1941,

Serial No. 391,219

14 Claims. (Cl. 260-396) quinones and substituted quinones and particularly to quinones of the benzene, naphthalen anthracene and pyrene series.

It is a principal object of the invention to prov de clean and efiicient processes for the production of quinones and substituted quinones utilizing economical ingredients and wherein the final products are produced in good yields and are easily separated and purified.

The invention is of especial usefulness in the Preparation of final products and intermediates of the quinone type and particularly for preparing Z-methyl-1,4-naphthoquinone, a compound having especially high vitamin K activity.

In carryin out the invention, an appropriate hydrocarbon of the benzene, naphthalene, benzanthracene or pyrene series is selected as the starting ingredient.

As the hydrocarbon starting materials suitable for use in the present invention, there may be used 1,4 unsubstituted benzenes having more than two positions substituted, unsubstituted naphthalene, 2-alkyl substituted naphthalenes, ,3-d1alkyl substituted naphthalenes, l-aldehyde substituted naphthalenes, benzanthracene or py- The selected starting material is subjected to the action of perhydrol (approximately hydrogen peroxide) in a suitable solvent and at elevated temperatures. The solvent must be such that it will dissolve the starting material and perhydrol and must not promote the decomposition of the reactants or resultant products. Glacial acetic acid fulfills these requirements and is Preferably used as the solvent, particularly because of its ready availability and low cost, although dioxane may also be used. The reaction is carried out at a temperature of from. 30-125 0., depending upon the type of hydrocarbon starting material used and upon manipulative factors, for a period ranging from a few minutes to a number of hours, depending upon the temperature used in the reaction, and the inherent reactability of the starting materials used.

- The reaction usually proceeds with characteristic color change, a yellow color being developed followed by a gradual change to cherry red.

The yields of final quinone'products are good,

"and recovery of the products 'in pure form is made by crystallization. steam distillation or sublimation, depending upon the characteristics of the final products.

The invention is illustrated by the following specific examples which, however, are not to be considered as limitations-upon the invention.

Example I as .a precipitate for the'distillate. A mixed melting point determination with gave no depression.

Example II an authentic sample A solution containing 4.03 grams'of 1-naphth- I aldehyde in 80 cc. of glacial acetic acid was treated with 25 cc. of perhydrol (3 hydrogen peroxide) on a steam bath. Within fifteen minutes the solution developed a yellow color, which as the reaction progresed, changed intoa cherry red color. The solution was concentrated by removal of half of the solvent by distillation, andwater was added drop by drop until preclpitation began. Two crops of crystals of 1,4 naphthoquinone were collected; the total yield being 1.1 grams. The 1,4 naphthoquinone had a melting point of l24-125 C., and a mixed melting point determination with an authentic sample of the same material proved identity of the resultant product.

. Example 111 A mixture composed of 10 grams 'of naphtha lene, 25 cc. of perhydrol and cc. of acetic acid I was heated together at just above 80 C. for fortyfive minutes. The volume of the reaction mixture was thereafter reduced to half by direct distillation 'at atmospheric pressure. Water was then added slowly until crystallization began; The first crop of 1,4-naphthoquinone obtained melted at 121-125? 0., and a second crop, began to melt at 115 C. After recrystallization a 20% yield of the 1,4-naphthoquinone was obtained.

Example IV Five grams of 2-methyl naphthalene was dissolved in cc. of glacial acetic acid solvent and warmed to 50 C. To this was added 15 cc. of perhydro] and the mixture was allowed to stand at for 10 hours. After an inductive periodduring, which no reaction apparently took place, the

solutionbegan to turn yellow andithen gradually developed acherry red color. "was evaporated and the material then steam distilled yielding 1.8 grams (30%) of 2-methyl- 1,4-naphthoquinone having a melting point of 104-105" C. The identity of the composition was shown by the fact that a mixed melting point determined with an authentic sample gave no depression in the melting point.

Example V Five grams of 2,3 dimethyl naphthalene was dissolved in 75 cc. of glacial acetic acid and warmed to 50 C. To this, there was added 15 cc. of perhydrol and the mixture treated in precisely the same way as in Example IV. The resultant product (2,3 dimethyl-1,4 naphthoqub,

none) was obtained without steam distillation in a 78% yield. The producthad a melting-.point of 127 C.

Example VI One gram of 1,2-benzanthracene was dissolved in 30 cc.'of glacial acetic acid and cc. of perhydrol was added. The solution was heated under reflux to the boiling point of the glacial acetic acid solvent, 1. e., approximately 115 C., and the flame removed. The exothermic reaction which ensued caused the mixture to continue refluxing for an additional ten minutes after which heating was continued for twenty minutes longer. The entire reaction mixture was then poured into The mixture of five grams of pyrene in 80 cc. of acetic acid was heated to the boiling point of glacial acetic acid and 25 cc. of perhydrol was added. After refluxing for twenty minutes at approximately 115 C., the reaction mixture was poured into cold water and a reddish precipitate was collected and dried. It weighed 5.1 grams.

This material is believed to be a mixture 01 3.8--

and 3,10-pyrene quinones, and was capable of being completely reduced by sodium hydrosulflte, showing that the product mixture consisted entirely of quinones.

The quinone products produced in accordance with this invention are of particular usefulness as intermediates, and in some instances, have individual usefulness. Thus, 2-methyl-1,4 naphthoquinone has high vitamin K activity and may be used. therefor; l,2-benzanthracene-9,10 is useful as an intermediate in the preparation of carcinogenic substances.

Many obvious variations may be made in the present invention without departing from the scope of the invention hereindescribed and claimed. .1

I claim as my invention:

1'. The process of producing quinones which comprises in the absence oia catalyst reactin an aromatic hydrocarbon selected from the class consisting of benzene having the 1 and 4 position unsubstituted and alkyl substituents in more than two positions, unsubstituted naphthalene, 2-alkyl substituted naphthalene, 2,3-dialkyl substituted The solvent naphthalene, l-aldehyde substituted naphthalene. 1,2-benzanthracene and pyrene, with approximately 30% concentration hydrogen peroxide in a solvent at elevated temperatures, continuing said reaction for a time period of minutes to 15 hours, depending upon the hydrocarbon used, until the corresponding quinone is formed and then separating the thus formed quinone.

2. The process of producing quinones which comprises in the absence of a catalyst reacting an aromatic hydrocarbon selected from the class consisting of benzene having the 1 and 4 position unsubstituted and alkyl substituents in more than two positions. unsubstituted naphthalene, 2-alkyl substituted naphthalene, 2,3-dialkyl substituted naphthalene, l-aldehyde substituted naphthalene. 1,2-benzanthracene and pyrene with approximately concentration hydrogen peroxide in glacial acetic acid, at elevated temperatures, continuing said reaction for a time period of 15 minutes to 15 hours, depending upon the hydrocarbon used. until the corresponding quinone is formed and then separating the thus formed quinone.

3. The process of producing quinones which comprises in the absence of a catalyst reacting an aromatic hydrocarbon selected from the class consisting of benzene having the 1 and 4 position unsubstituted and alkyl substituents in more than two positions, unsubstituted naphthalene, 2,3-dialkyl substituted naphthalene, l-aldehyde substituted naphthalene, 1,2-benzanthracene and pyrene with approximately 30% concentration hydrogen peroxide in glacial acetic acid at a temperature between 30 C. and 125 C., continuing said reaction for a time period of 15 minutes to 15 hours, depending upon the hydrocarbon used, until the corresponding quinone is formed and then separating the thus formed quinone.

4. The process which comprises in the absence of a catalyst reacting Z-methyl naphthalene with approximately 30% concentration hydrogen peroxide in a solvent at elevated temperatures for about 10 hours and then separating the thus formed 2-methyl-1,4-naphthoquinone.

5. The process which comprises in the absence of a catalyst reacting 2-methyl naphthalene with perhydrol in glacial acetic acid at an elevated rating the thus formed 2-methyl-1,4'-naphthoquinone.

6. The process which comprises in the absence of a. catalyst heating a mixture 2-methyl naphthalen in glacial acetic acid, then adding perhydrol and heating for several hours at an increased temperature and then separating the thus formed Z-methyl-1,4-naphthoquinone.

7. The process which comprises in the absence of a catalyst heating a mixture of Z-methylnaphthalene in glacial acetic acid to about 50 C., adding hydrogen peroxide of about 30% concentration and continuing the reaction by allowing the mixture to stand at about C. for about 10 hours and then separating the thus formed Z-methyl-1,4-naphthoquinone.

- 8. The process of producing quinones by limited direct oxidation which comprises reacting a benzenoid compound having a reactivity level in excess of that of the dialkyl substituted benzene; and selected from the group consisting of benzene having positions available for quinone formation and alkyl substituents in more than two positions.

unsubstituted naphthalene, z-alkyl substituted naphthalene, 2,3-dialkyl substituted naphthalene.

l-aldehyde substituted naphthalene, 1,2-benzanstituted naphthalene, 2,3-dialkyl thracene and pyrene, with hydrogen peroxide 01' about concentration, said reaction being .carried out in a solvent capable of dissolving the 1 benzenoid compound and hydrogen peroxide, the solvent being further characterized in that it does promote the decomposition of the reactants or resultant quinones, said reaction being carried out in the absence of a catalyst, continuing said reaction only until quinones are produced and then interrupting the reaction and separating the thus formed quinones.

9. The process of producing quinones by limited direct oxidation which comprises reacting a vent and in the absence of a catalyst, continuing said reaction only until quinones are produced and then interrupting the reaction and separat-' ing the thus formed quinones. 7

10. The process of producing quinones by limited direct oxidation which comprises reacting a benzenoid compound having a reactivity level inexcess oi that of the dialkyl substituted benzenes and selected from the group consisting of benzene having positions appropriate for quinone formation and alkyl substituents in more than two positions, unsubstituted naphthalene, 2-alkyl subsubstituted naphthalene, l-aldehyde substituted naphthalene, 1,2-benmnthracene and pyrene, with perhydrol,

. said reaction being carried out in glacial acetic acid solvent and in the absence of a catalyst, continuing said reaction only until quinones are produced and then interrupting the reaction and separating the thus formed quinones.

11. The process of producing quinones by limited direct oxidation which comprises reacting a -benzenoid compound having a reactivity level in excess of that of the dialkyl substituted benzenes and selected from the group consisting of benzene having the positions appropriate for quinone formation and alkyl substituents in more than two positions, unsubstituted na hthalene, 2-alkyl substituted naphthalene, 2,3-dialkyl substituted naphthalene, i-aldehyde substituted naphthalene,

1,2-benzanthracene and pyrene, with hydrogen peroxide of approximately 30% concentration, said reaction being carried out in glacial acetic acid solvent at a temperature 01! 30 to 125 C. and in the absence of a catalyst, continuing said reaction only until quinones are; produced and then interrupting the reaction and separating the thus formed quinones.

12. The process or producing. 2-methyl-1,4- naphthoquinone which comprises reacting 2-methyl naphthalene with hydrogen peroxide of approximately 30% concentration at a temperature between 30 C. and 125 C. in the presence of a solvent but without a catalyst, said reaction being continued until a cherry red color is developed, and thereafter separating the thus formed 2-methyl-1,4-naphthoquinone.

13. The process of producing 2-methyl-L4- V naphthoquinone which comprises l reacting Z-methyi naphthalene and perhydrol in glacial acetic acid solvent in the absence of a catalyst at a temperature of about 30 C. to 125 C. until a cherry red color is developed, and thereafter separating the thus formed 2-methyI-L4-naphthoquinone.

14. The process of producing 2-methyl-1,4- naphthoquinone which comprises reacting 2-methyl naphthalene and perhydrol in the proportions oi. about 5 grams of the former to about 15 cc. of the latter, the reaction being carried out in glacial acetic acid inthe absence of a catalyst at a temperature of about C. until a cherry red color is developed, and then separating the thus formed 2-methyI-L4-naphthoquinone.

RICHARD T. ARNOLD. 

